Electric relay for radiography



'June 28,1927. 1,634,208

' H. P. PILON ELECTRIC RELAY FOR RADIOGBAPHY Filed Sept. 1925 Patented June 28, 1927.

; Hadron rm. riton, or rams, FRANCE.

swarm RELAY FOR RAnIoeRA'rHYQ 7 A lication med see aw 2 4 1925; Serial no. 533,462, an in fraud iv'ovember 18, 1924.

I Actually, the operator who is to effect a radiography, reviously determines the quality of the -ra diation which is a function of the potential applied at the terminals of the X-ray bulb, the intensity of this radiation which is proportional to the average intensity of the current passing through the bulb, and the quantity of energy of the X-r'adia'tion necessary for the correct impression of the photographic emulsion, quantity which is proportional to the time or duration of passage of the current.

If it is'supposed that the above mentioned factors: otential and intensity are perfectly exact and constant, in case the time of eXp0- sure is rather long, the operator can easily maintain the constancy of these factorsfby means of the usual adjusting devices. But, when the time of exposure is very short, the measurements ofthe intensity and of the potential are very difficult and it is not to be thought of maintaining them constant by hand adjustment. I

It is to be noted that it is precisely in rapid radiographies, in which the intensities are very high, that thevariations of tension and intensity are the greatest. It results therefrom that with the means generally used, rapid radiographies can be 3 obtained only by an empirical evaluation of the various factors under consideration. Moreover, the realization of contacts of short duration and of great exactness is, practically, impossible.

The present invention has for its object to provide an apparatus automatically taking into account all the possible variations of intensity and of potential, for supplymg the bulb with a predetermined quantity of "1 energy, with factors initially adjusted to the required value. The apparatus determines the time of ex osure according to these values and modi es it according to the variations which may occur.

Substantially, this apparatus is constituted by a movable equipment of electric meter carrying a contact sending or cutting olf, at the end of its displacement, the current in a contactor-relay controlling the main current. The displacement o the equipment is adjustable. beforehand by means of a movable abutment rigid with an index moving over a dial graduated in units of energy used.

The movable equipment of this meter is urged by a force proportional to the energy y suitably arranged windings branched on the tension and lntensity circuits of the curpassing through the bulb and which is given J rent feeding the radiogeneous bulb or on the primary circuit of the high tension transformer.

By way of example, the accompanying drawing illustrates a form of carrying out the invention.

The rotating switch 1 being put in synchronism and brought into step, the contact 2 is closed. The current is thensent in the closin'gcoil 3, the switch 4 is attracted and closes the former. 1 l p The current flowing I, through the X-ray tube 7 passes through the secondary circuit 6 of" the transformer and through the cur primary circuit'5 of the transrent coil 8 of the series relay in said circuit.

This current-coilS anda voltagecoilnS) produce a torque acting on a metal disc 10 the speed of rotation of which is determined for a given intensity, by an adjustable magnet 11 creating an antagonistic torque. A relay contact 12, rigid with the disc, has its starting point determined by an adjustable abutment 13.

This contact 12 is caused, by the rotation of the disc, to short-circuit the contact 14, the current then passes in the releasing or tripping coil 15 which attracts the switch and opens the primary circuit of the transformer.

The speed of rotation of the disc is proportional to the intensity and voltage applied at the terminals of their respective coils. It might be supposed that this voltage coil is branched at the terminals of the primary circuit of the transformer.

The mode of operation is as follows:

After having adjusted through the index of the graduated dial the starting point 13 of the displacement of'the movable equipment 10-12 in accordance with the quantity of energy it is desired to pass in the bulb, the current of the contactor-relay 3 of the. main current is cut inv by means of the auxiliary switch 2. The X-ray bulb 7 is fed according to the constants chosen and the movable equipment of the meter 10 advances at a speed which depends on the electric braking of the movable equipmentlO-lQ so as to calibrate the graduated dial according to the shape of the current used in the radiogeneous bulb 7.

lVhat I claim as my invention and desire to secure by Letters Patent is 1. In an X-ray photographic apparatus, a transformer for supplying an X-ray tube and including primary and secondary windings, a field winding shunt connected with the primary winding of the transformer, a second lield winding connected in series with the secondary winding of the transformer to produce with the first field winding a nmgnetic tield, a rotatable disc aranged in said magnetic held, and means for opening the circuit of the transformer primary winding upon rotation oi the disc to a predetermined extent.

2. in an X ray photographic apparatus, a transformer for supplying an X-ray tube and including primary and secondary windings and circuits associated therewith, a field winding shunt connected with the primary Winding of the transformer, a second field winding connected in series with the secondary winding of the transformer to produce with the first mentioned field winding a magnetic field, a rotatable disc arranged in said magnetic field, means for opening the primary circuit of the transformer after a predetermined rotation of said disc, and means for varying the extent of rotary motion of the disc necessary to effect the opening of said primary circuit.

3. In an X-ray photographic apparatus, a transformer for supplying an X-ray tube and including primary and secondary windings and circuits associated therewith, a field winding shunt connected with the primary winding of the transformer, a second field winding connected in series with the second ary winding of the transformer to produce with the first mentioned lield winding a magnetic field, a rotatable disc arranged in said magnetic field, a relay including means for opening the primary circuit of the transformer, and a circuit including said relay, means for closing the relay circuit after a predetermined rotation of said disc to energize said relay and effect the opening of the transformer primary circuit, and means for 'arying the extent of rotary motion of the disc necessary to effect the closing of the relay circuit.

In testimony whereof I have signed my name to this specification.

HECTOR PAUL PILON. 

